Light emitting device and fused polycyclic compound for the light emitting device

A light emitting device comprising:

• a first electrode;
• a second electrode facing the first electrode;
• and
• an emission layer between the first electrode and the second electrode, wherein
• the emission layer comprises:
• a first compound represented by Formula 1;
• and
• at least one of a second compound represented by Formula HT-1 or a third compound represented by Formula ET-1:
• wherein in Formula 1,
• X1 is a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms,
• Y1 is a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms,
• R1 to R3 and Ra to Rj are each independently a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted silyl group, a substituted or unsubstituted amine group, a substituted or unsubstituted oxy group, a substituted or unsubstituted thio group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, or are bonded to an adjacent group to form a ring,
• at least one of Ra to Rj is each independently a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms,
• n1 is an integer from 0 to 2,
• n2 is an integer from 0 to 4, and
• n3 is an integer from 0 to 3,
• wherein in Formula HT-1,
• L1 is a direct linkage, a substituted or unsubstituted arylene group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroarylene group having 2 to 30 ring-forming carbon atoms,
• Y is a direct linkage, C(Ra3)(Ra4), or Si(Ra5)(Ra6),
• Ar1 is a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms,
• Ra1 to Ra6 are each independently a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted silyl group, a substituted or unsubstituted thio group, a substituted or unsubstituted oxy group, a substituted or unsubstituted amine group, a substituted or unsubstituted boron group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, or are bonded to an adjacent group to form a ring, and
• m1 and m2 are each independently an integer from 0 to 4,
• wherein in Formula ET-1,
• at least one of Z1 to Z3 is each N,
• the remainder of Z1 to Z3 are each independently C(Ra3),
• Ra3 is a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 60 ring-forming carbon atoms,
• b1 to b3 are each independently an integer from 0 to 10,
• L2 to L4 are each independently a direct linkage, a substituted or unsubstituted arylene group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroarylene group having 2 to 30 ring-forming carbon atoms, and
• Ar2 to Ar4 are each independently a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms.